import java.util.concurrent.Semaphore;
// 信号量当为1的时候可以当成锁来使用
public class Demo43 {
    private volatile static int count = 0;
    public static void main(String[] args) throws InterruptedException {
        Semaphore semaphore = new Semaphore(1);
        Thread t1 = new Thread(() -> {
           for(int i = 0; i < 50000 ; i++){
               try {
                   semaphore.acquire();
                   count++;
                   semaphore.release();
               } catch (InterruptedException e) {
                   throw new RuntimeException(e);
               }
           }
        });
        Thread t2 = new Thread(() -> {
           for(int i = 0; i < 50000; i++) {
               try {
                   semaphore.acquire();
               } catch (InterruptedException e) {
                   throw new RuntimeException(e);
               }
               count++;
               semaphore.release();
           }
        });
        t1.start();
        t2.start();
        t1.join();
        t2.join();
        System.out.println(count);
    }
}
